A comparison of two methods of bone-age estimation has been made using the hand and wrist radiographs of 66 boys and 58 girls. An estimate made using the specialist auxological technique of Tanner and Whitehouse was compared with three separate estimates obtained by the atlas matching method of Greulich and Pyle (1971). Two of the latter estimates were carried out by two dedicated radiologists whose results showed close agreement. The third estimate made using the Greulich and Pyle method was derived from the routine reports of a number of radiologists at initial presentation. Only in one narrow age-range for girls was there a significant inter-observer difference, and the reasons for this are discussed. Estimates made using the method of Greulich and Pyle were younger than those made using that of Tanner and Whitehouse. There was a linear relationship between the two methods for the boys but not for the girls. It is suggested that atlas matching methods still have a valuable place in non-specialist hospitals concerned with initial diagnosis rather than with the long-term care of growth problems.